function jspang(...arg){
    console.log(arg[0]);
    console.log(arg[1]);
    console.log(arg[2]);
    console.log(arg[3]);
}

jspang(1,2,3);

let arr1=["www","JSPang","com"];
// let arr2=arr1;
let arr2=[...arr1];
console.log(arr2);

arr2.push("hongyu");
console.log(arr2);
console.log(arr1);
